1,721,121 research outputs found
Bézier-based biased random-key genetic algorithm to address printability constraints in the topology optimization of concrete structures
No full textThe advancements of additive manufacturing (AM) technologies are typically coupled with research addressing topology optimization, whose aim is to use optimization methods to achieve effective expressions of free-form design. While many studies emphasize the breakthroughs that topology optimization could bring into structural engineering, there are just a few scientific contributions that address design feasibility, accounting for the technological constraints that characterize the different AM techniques. By formulating a stress-constrained topology optimization problem with a more technologically oriented approach, this study aims to optimize concrete structures while enforcing the cross-section width and path-traceability restrictions that affect the feasibility and performance of geometries obtained through the layered extrusion technique. In particular, this paper proposes a curve-based Biased Random-Key Genetic Algorithm that optimizes stress-constrained structures and generates topologies that can be implemented without post-processing operations. The proposed algorithm, when tested on a diverse set of concrete beam configurations, effectively achieved optimized solutions that used between 81 % and 75 % less material than the full beam configuration. Additionally, each one of the designed topologies adequately met the stress requirements and process-specific constraints. Lastly, two experimental cases also highlighted the printability effectiveness of the proposed approach in conjunction with design of optimized solutions
Olivicoltura di Canino: Proposte di valorizzazione della produzione
No full textL'andamento della produzione di olive e olio nell'area di Canino è stata esaminata in relazione a fattori climatici ed agronomici. Indirizzi di scelta varietale e di tecnica colturale vengono illustrati in funzione di un possibile miglioramento della produzione e della conservazione della tipicità dell'olio, con particolare riferimento alla cultivar locale Caninese (Canino)
Combining Multiple Loads in a Topology Optimization Framework for Digitally Fabricated Concrete Structures
No full textIn recent literature, topology optimization gathered growing interests given its interplays with digital fabrication and additive manufacturing technologies. Notably, the topological optimization of concrete-like elements requires the study of stress-constrained optimization problems due to strength anisotropy, whose solution presents more challenges with respect to classical stiffness-to-weight maximization. For the purpose of fostering the use of topology optimization techniques in real-application scenarios, in this work we present an iterative algorithm to design lightweight structural concrete elements in presence of multiple load actions, and under the restriction of anisotropic stress-constraints. More specifically, our framework is based on the combined use of a proportional material distribution scheme and a Risk-Factor paradigm, to design performative solutions while limiting the failure probability of the structural element. To validate our approach, we define a parametric set of actions which combine bending and axial load, as commonly utilized in a structural engineering framework. In our computational experiments, we assess the robustness of our method and study the relationships connecting load parameters with the resulting solution properties
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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